The present invention relates to a device which is adapted to provide a sealing effect between a window or door wing or the like and a frame associated therewith.
Devices of the aforementioned kind are per se known. Where such devices are used, the gap existing between the wing and the frame is sealed by means of a pressurized tube disposed therebetween. With the window or door in its closed position, said hose is filled with a pressurized liquid by means of a pump so that the tube is forced against the respective sealing surfaces so as to close the gap. Such a device is disclosed, for example, in DE-OS No. 20 44 686. In this known device, the pump is comprised of an elongated tray which is closed by means of a slidably movable plate. This elongated plate is adapted to be slidably moved by means of an inclined cam surface and a roller cooperating with the cam surface. The roller is connected to a scissors-like system of levers which is adapted to be operated either independently or together with the operating handle of the wing. Upon the window being closed, operation of the handle of the wing will cause the system of levers to be actuated, this causing pressure to be exerted on the movable plate of the pump so that it reduces the volume of the pump, this, in turn, causing liquid to be forced into the sealing hose.
Similar devices are disclosed in DE-OS No. 21 40 753 and DE-OS No. 22 13 066. In these latter devices, the pump is accommodated in the frame of the window or door and is adapted to be actuated by the mechanical closing members serving to lock the window.
It is a disadvantage of said known devices that they are not suitable for use with windows and doors covering large areas. This disadvantage results from the fact that, with said known devices, closing the window will cause the pump to perform a single stroke only and that this single stroke is required to force into the sealing tube the entire amount of liquid required for producing said sealing effect. In the case of windows of very large size this means that the pump reservoir is required to have a very large surface area. On the other hand, however, in the window frame space is at a premium. Moreover, in the case of such large-area, single-stroke pumps, a complicated system of levers is required for moving the pressure plate in order uniformly to distribute the required forces throughout the pressure plate and to prevent the pressure plate from being tilted in an undesirable manner.
Another disadvantage of the said known devices resides in the fact that it is impossible to vary the pressure exerted on the sealing tube during closing of the window. The maximum possible pressure is always produced when the window is closed. However, with a given quantity of liquid contained in the pressure tube, the maximum pressure is subjected to considerable variation as a function of temperature. Thus, very high temperatures will result in a high pressure which might cause damage to the tube system. If it is desired to counteract this effect with said conventional devices, the respective system will have to be designed for the maximum pressure to be expected at high temperatures. Therefore, the maximum pressure for sealing will not be attained at normal temperatures. The sealing effect is thus reduced at lower temperatures, i.e. in cold weather, although a particularly reliable sealing effect would be desirable under such weather conditions.